<template>
  <div class="app-container">
    <h2 style="text-align: center">发布新课程</h2>
    <el-steps
      :active="1"
      process-status="wait"
      align-center
      style="margin-bottom: 40px"
    >
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>
    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input
          v-model="courseInfo.title"
          placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"
        />
      </el-form-item>
      <el-form-item label="课程分类">
        <!-- 一级分类 -->
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="请选择一级分类"
          @change="subjectLevelOneChanged"
        >
          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>
        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="请选择二级分类">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>
      </el-form-item>

      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select v-model="courseInfo.teacherId" placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"
          />
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number
          :min="0"
          v-model="courseInfo.lessonNum"
          controls-position="right"
          placeholder="请填写课程的总课时数"
        />
      </el-form-item>
      <!-- 课程简介 TODO -->
      <!-- <el-form-item label="课程简介">
        <el-input
          v-model="courseInfo.description"
          controls-position="right"
          placeholder="请填写课程简介"
        />
      </el-form-item> -->
      <!-- 课程简介-->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>
      <!-- 课程封面-->
      <el-form-item label="课程封面">
        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API + '/eduoss/fileoss'"
          class="avatar-uploader"
        >
          <img :src="courseInfo.cover"/>
        </el-upload>
      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number
          :min="0"
          v-model="courseInfo.price"
          controls-position="right"
          placeholder="免费课程请设置为0元"
        />
        元
      </el-form-item>
      <el-form-item>
        <el-button
          :disabled="saveBtnDisabled"
          type="primary"
          @click="saveOrUpdate"
        >保存并下一步
        </el-button
        >
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
  import course from "@/api/edu/course";
  import subject from "@/api/edu/subject";
  import Tinymce from "@/components/Tinymce";

  const defaultForm = {
    title: "",
    subjectId: "",
    subjectParentId: "",
    teacherId: "",
    lessonNum: 0,
    description: "",
    cover: "/static/01.png",
    price: 0,
  };
  export default {
    components: {Tinymce},

    data() {
      return {
        courseInfo: defaultForm,
        saveBtnDisabled: false, // 保存按钮是否禁用
        teacherList: [],
        subjectOneList: [],
        subjectTwoList: [],
        BASE_API: process.env.BASE_API,
      };
    },
    watch: {
      $route(to, from) {
        console.log("watch $route");
        this.init();
      },
    },
    created() {
      //获取路由中的ID值
      if (this.$route.params && this.$route.params.id) {
        this.courseId = this.$route.params.id
        //调用根据地查询课程的方法
        this.getInfo()
      } else {
        //初始化所有讲师
        this.getListTeacher()
        //初始化一级分类
        this.getOneSubject()
      }

      this.init();
      //初始化讲师数据
      this.getListTeacher();
      //获取所有一级分类数据
      this.getOneSubject();
    },
    methods: {
      //根据课程ID查询课程信息
      getInfo() {
        course.getCourseInfoId(this.courseId).then(response => {
          this.courseInfo = response.data.courseInfoVo
          //查询所有的分类,包含一级和二级
          subject.getSubjectList().then(response => {
            //获取所有一级分类
            this.subjectOneList = response.data.list;
            //所有一级分类数据进行遍历,比较当前courseInfo里的一级分类ID是否一致
            for (var i = 0; i < this.subjectOneList.length; i++) {
              var oneSubject = this.subjectOneList[i];
              if (oneSubject.id == this.courseInfo.subjectParentId) {
                //获取一级分类中的所有二级分类
                this.subjectTwoList = oneSubject.children
              }
            }
          })
          this.getListTeacher()
        })
      },
      // 上传成功
      handleAvatarSuccess(res, file) {
        this.courseInfo.cover = res.data.url;
      },
      //上传之前
      beforeAvatarUpload(file) {
        const isJPG = file.type === 'image/jpeg' || file.type === 'image/png';
        const isLt2M = file.size / 1024 / 1024 < 2;
        if (!isJPG) {
          this.$message.error('上传头像图片只能是 JPG 格式!');
        }
        if (!isLt2M) {
          this.$message.error("上传头像图片大小不能超过 2MB!");
        }
        return isJPG && isLt2M;
      },

      //点击某个一级分类触发的时间,显示对应的二级分类
      subjectLevelOneChanged(value) {
        //value就是一级分类的ID值
        //从一级分类获取里面的所有的二级分类
        for (var index = 0; index < this.subjectOneList.length; index++) {
          var oneSueject = this.subjectOneList[index];
          if (value === oneSueject.id) {
            this.subjectTwoList = oneSueject.children;
          }
        }
        //选择一级分类之后,二级分类选择的值清空
        this.courseInfo.subjectId = "";
      },

      //查询所有一级分类
      getOneSubject() {
        subject.getSubjectList().then((response) => {
          this.subjectOneList = response.data.list;
        });
      },

      //查询所有讲师
      getListTeacher() {
        course.getListTeacher().then((response) => {
          this.teacherList = response.data.items;
        });
      },

      //添加课程信息
      addCourse() {
        course.addCourseInfo(this.courseInfo).then((response) => {
          //提示
          this.$message({
            type: "success",
            message: "添加课程信息成功",
          });
          //跳转到第二步
          this.$router.push({
            path: "/course/chapter/" + response.data.courseId,
          });
        });
      },

      //修改课程信息
      updateCourse() {
        course.updateCourseInfo(this.courseInfo).then((response) => {
          //提示
          this.$message({
            type: "success",
            message: "修改课程信息成功",
          });
          //跳转到第二步
          this.$router.push({
            path: "/course/chapter/" + this.courseId,
          });
        });
      },

      //保存或修改课程信息
      saveOrUpdate() {
        if (!this.courseInfo.id) {
          //添加
          this.addCourse()
        } else {
          //修改
          this.updateCourse()
        }
      },

      init() {
        if (this.$route.params && this.$route.params.id) {
          const id = this.$route.params.id;
          console.log(id);
        } else {
          this.courseInfo = {...defaultForm};
        }
      },
    },
  };
</script>

<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
